U.S. patent number 10,626,516 [Application Number 16/088,910] was granted by the patent office on 2020-04-21 for electrolytic copper foil for graphene and method for producing the copper foil.
This patent grant is currently assigned to ILJIN MATERIALS CO., LTD.. The grantee listed for this patent is ILJIN MATERIALS CO., LTD.. Invention is credited to Tae Jin Jo, Sun Hyoung Lee, Seul-Ki Park, Ki Deok Song.
United States Patent |
10,626,516 |
Jo , et al. |
April 21, 2020 |
Electrolytic copper foil for graphene and method for producing the
copper foil
Abstract
The present disclosure relates to an electrolytic copper foil
for graphene and a method for producing the copper foil, in which,
in the manufacture of the electrolytic copper foil for graphene,
addition of nickel facilitates the synthesis of the graphene. The
addition of nickel which serves as a seed in the synthesis of
graphene on electrolytic copper foil reduces the electrical
conductivity after graphene synthesis. As a result, graphene is
uniformly formed on the surface of the copper foil. Further, the
present disclosure may provide the electrolytic copper foil for
graphene and the method for producing the copper foil in which an
electrolytic copper foil having a resistance value of less than 300
ohm/square after the synthesis of the graphene on the electrolytic
copper foil is produced, thereby, facilitate the formation of
graphene on the electrolytic copper foil.
Inventors: |
Jo; Tae Jin (Iksan,
KR), Lee; Sun Hyoung (Iksan, KR), Park;
Seul-Ki (Iksan, KR), Song; Ki Deok (Iksan,
KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
ILJIN MATERIALS CO., LTD. |
Iksan |
N/A |
KR |
|
|
Assignee: |
ILJIN MATERIALS CO., LTD.
(Iksan, KR)
|
Family
ID: |
60160767 |
Appl.
No.: |
16/088,910 |
Filed: |
March 21, 2017 |
PCT
Filed: |
March 21, 2017 |
PCT No.: |
PCT/KR2017/003007 |
371(c)(1),(2),(4) Date: |
September 27, 2018 |
PCT
Pub. No.: |
WO2017/188601 |
PCT
Pub. Date: |
November 02, 2017 |
Prior Publication Data
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|
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Document
Identifier |
Publication Date |
|
US 20190071790 A1 |
Mar 7, 2019 |
|
Foreign Application Priority Data
|
|
|
|
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Apr 28, 2016 [KR] |
|
|
10-2016-0052528 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C25D
5/50 (20130101); C01B 32/186 (20170801); C25D
7/0614 (20130101); C25D 1/04 (20130101); C01B
32/182 (20170801); C25D 3/38 (20130101); B82Y
30/00 (20130101); B82Y 40/00 (20130101); Y10T
428/12431 (20150115); Y10T 428/12438 (20150115) |
Current International
Class: |
B21C
37/00 (20060101); C25D 5/50 (20060101); C01B
32/186 (20170101); C01B 32/182 (20170101); C25D
3/38 (20060101); C25D 1/04 (20060101); C25D
7/06 (20060101); B82Y 30/00 (20110101); B82Y
40/00 (20110101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
0857402 |
|
Dec 2007 |
|
EP |
|
2001-123290 |
|
Mar 2001 |
|
JP |
|
2013107036 |
|
Jun 2013 |
|
JP |
|
10-2000-0064294 |
|
Nov 2000 |
|
KR |
|
10-0364685 |
|
Apr 2003 |
|
KR |
|
10-0560672 |
|
Mar 2006 |
|
KR |
|
10-2014-0043133 |
|
Apr 2014 |
|
KR |
|
2011/129633 |
|
Oct 2011 |
|
WO |
|
WO2011129633 |
|
Oct 2011 |
|
WO |
|
Primary Examiner: Dumbris; Seth
Attorney, Agent or Firm: Patent Office of Dr. Chung Park
Claims
What is claimed is:
1. An electrolytic copper foil for synthesis of graphene, wherein
the electrolytic copper foil before thermal treatment has a tensile
strength of 45 to 70 kgf/mm.sup.2 at a room temperature, wherein
the electrolytic copper foil after the thermal treatment has a
tensile strength of 20 to 35 kgf/mm.sup.2 at a room temperature,
wherein the electrolytic copper foil includes nickel, the nickel,
which serves as a seed in synthesis of graphene on the electrolytic
copper foil, reduces electrical conductivity after the synthesis of
the graphene on the electrolytic copper foil so that the graphene
is uniformly formed on a surface of the electrolytic copper foil,
and wherein a resistance of the copper foil after the synthesis of
the graphene on the electrolytic copper foil is equal to or less
than 300 .OMEGA./square.
2. The electrolytic copper foil of claim 1, wherein the thermal
treatment is carried out at a temperature of 180 to 220 degrees
Celsius for 50 to 80 minutes.
3. The electrolytic copper foil of claim 1, wherein a thickness of
the electrolytic copper foil is 4 to 70 .mu.m.
Description
BACKGROUND
1. Technical Field
The present disclosure relates to an electrolytic copper foil for
graphene and a method for producing the copper foil. More
particularly, the present disclosure relates to an electrolytic
copper foil for graphene and a method for producing the copper
foil, in which, in the manufacture of the electrolytic copper foil
for graphene, addition of nickel may facilitate the synthesis of
the graphene.
2. Description of Related Art
A graphene is a term made by combining the graphite used as a
pencil lead and the suffix "-ene" representing a molecule with
carbon double bonds. Graphite has a structure in which carbon
layers of hexagonal honeycomb are stacked. The graphene may be
considered to be one thinnest layer as removed from the graphite.
The graphene, a carbon isotope, is a nanomaterial composed of
carbon atoms such as carbon nanotubes and Fullerene. Graphene has a
two-dimensional planar shape. The thickness of the graphene is 0.2
nm (1 nm is one-billionth of one meter), which is extremely thin.
That is, the thickness of graphene is extremely thin, that is,
about two-billionths of one meter. Furthermore, the physical and
chemical stability of graphene is high.
Further, graphene has more than 100 times more electricity than
copper. Graphene can move electrons more than 100 times faster than
monocrystalline silicon, which is mainly used as a semiconductor.
The strength of graphene is 200 times stronger than steel. The
thermal conductivity of graphene is two times higher than that of
diamond with the highest thermal conductivity. Furthermore, the
graphene's elasticity is excellent, so that it does not lose its
electrical properties even when it is stretched or bent.
Due to these properties, graphene is regarded as a material that
goes beyond carbon nanotubes, which are attracted by the next
generation of new materials, and is called a dream nanomaterial.
Graphene and carbon nanotubes have very similar chemical
properties. In those materials, metallic and semiconducting
properties may be separated from each other by a post-process.
However, because graphene has a more uniform metallicity than
carbon nanotubes, the graphene is more likely to be applied
industrially. Further, graphene is attracting attention as a
future-oriented new material in the electronic information
industry, which may allow production of bendable displays,
electronic paper, and wearable computers.
In 2004, the Geim and Novoselov teams at the University of
Manchester became the first to succeed in separating atomic layers
from graphite with Scotch tape. As a result, graphene was invented.
They were awarded the 2010 Nobel Prize in Physics. In 2010,
roll-to-roll technology, which transfers 30-inch large-area
graphene was developed. In 2013, a specific roll-to-roll graphene
synthesis technology that goes beyond the idea level has been
unveiled. Thereafter, the development of graphene continues to be
commercialized.
However, it is important to uniformly realize a single-layer
graphene thin film in order to utilize graphene industrially. The
number of layers of the graphene sheet as obtained by the method of
peeling the graphene using the adhesive tape is not constant. In
this case, a large-area graphene sheet is not easily obtained. This
method has a problem that it is not suitable for mass
production.
Further, in the prior art, there is a problem that multi-layer
graphene on the copper foil is distributed in an island shape and
grows non-uniformly, and amorphous carbon coexists with graphene/As
a result, it is difficult to obtain clean single-layer graphene
and, thus, the conductivity is deteriorated.
DISCLOSURE OF INVENTION
Technical Purposes
The present disclosure is to provide an electrolytic copper foil
for graphene and a method for producing the copper foil in which,
in the synthesis of graphene on the electrolytic copper foil,
adding nickel serving as a seed may allow lowering an electrical
conductivity after graphene synthesis.
Further, the present disclosure is to provide an electrolytic
copper foil for graphene and a method for producing the copper foil
in which an electrolytic copper foil having a resistance value of
less than 300 ohm/square after the synthesis of the graphene on the
electrolytic copper foil is produced, thereby, facilitate the
formation of graphene on the electrolytic copper foil.
Technical Solutions
In one embodiment of the present disclosure, there is provided an
electrolytic copper foil for graphene, wherein the electrolytic
copper foil has a tensile strength of 45 to 70 kgf/mm.sup.2 at a
room temperature, wherein the electrolytic copper foil after
thermal treatment has a tensile strength of 20 to 35 kgf/mm.sup.2
at a room temperature.
Further, the thermal treatment may be carried out at a temperature
of 180 to 220 degrees Celsius for 50 to 80 minutes.
Further, a thickness of the electrolytic copper foil may be 4 to 70
.mu.m.
Further, a resistance of the copper foil after synthesis of the
graphene on the electrolytic copper foil for the graphene may be
300 .OMEGA./square or smaller.
In another embodiment of the present disclosure, there is provided
a method for producing an electrolytic copper foil for graphene,
wherein plating of the copper foil is performed in a copper
electrolytic solution under a condition that a nickel concentration
in the copper electrolytic solution is kept at 1000 ppm or lower
and a chlorine concentration in the copper electrolytic solution is
kept at 1 ppm or lower.
Further, plating of the copper foil is performed in a copper
electrolytic solution under a condition that a total organic carbon
(TOC) concentration in the copper electrolytic solution may be kept
at 3 ppm or lower.
Further, when plating the copper foil, a temperature of the
electrolytic solution is 30 to 70 degree C. and a current density
may be 30 to 140 ASD.
Further, when plating the copper foil, a copper concentration in
the electrolytic solution may be 60 to 140 g/L, and a sulfuric acid
concentration in the electrolytic solution may be 70 to 200
g/L.
Technical Effects
In accordance with the present disclosure, the addition of nickel
which serves as a seed in the synthesis of graphene on electrolytic
copper foil reduces the electrical conductivity after graphene
synthesis. As a result, graphene is uniformly formed on the surface
of the copper foil.
Further, the present disclosure may provide the electrolytic copper
foil for graphene and the method for producing the copper foil in
which an electrolytic copper foil having a resistance value of less
than 300 ohm/square after the synthesis of the graphene on the
electrolytic copper foil is produced, thereby, facilitate the
formation of graphene on the electrolytic copper foil.
DETAILED DESCRIPTIONS
The details of other embodiments are included in the detailed
description and drawings.
The advantages and features of the present disclosure, and how to
accomplish them, will become apparent with reference to the
embodiments described in detail below with reference to the
accompanying drawings. However, the present disclosure is not
limited to the embodiments disclosed below but may be implemented
in various other forms. In the following description, when a
certain portion is connected to another portion, this includes not
only the case where they are directly connected but also the case
where they are connected via another medium therebetween. Further,
parts of the drawing that do not relate to the present disclosure
have been omitted to clarify the description of the present
disclosure. Like parts are designated with like reference numerals
throughout the specification.
Hereinafter, the present disclosure will be described in
detail.
The present disclosure relates to an electrolytic copper foil for
graphene and a method for producing the copper foil. More
particularly, the present disclosure relates to an electrolytic
copper foil for graphene and a method for producing the copper
foil, in which, in the manufacture of the electrolytic copper foil
for graphene, addition of nickel may facilitate the synthesis of
the graphene.
In accordance with the present disclosure, the electrolytic copper
foil has a tensile strength of 45 to 70 kgf/mm.sup.2 at a room
temperature. The electrolytic copper foil after thermal treatment
has a tensile strength of 20 to 35 kgf/mm.sup.2 at a room
temperature.
During the process of manufacturing electrolytic copper foil for
graphene, graphene was synthesized on electrolytic copper foil. In
this synthesis process, the temperature of the electrolytic copper
foil will rise to 1000 degrees Celsius. At such a high temperature,
the grain of the copper foil surface must be grown to a certain
size such that the synthesis of graphene is easy. When the grain
grows to the certain size, the tensile strength is lowered to a
certain range. In the present disclosure, the range of the tensile
strength at room temperature of the electrolytic copper foil where
graphene synthesis is easy, and the range of tensile strength
measured at room temperature after the thermal treatment thereof
where graphene synthesis is easy was measured and defined. The
ranges may be as described above. For reference, the thermal
treatment of the electrolytic copper foil is preferably performed
at a temperature of 180 to 220 degrees Celsius for 50 to 80
minutes.
Further, in one embodiment, the thickness of the electrolytic
copper foil may be 4 to 70 .mu.m. When the thickness of the
electrolytic copper foil is smaller 4 .mu.m, the electrolytic
copper foil tends to be broken and, thus, the handling property in
the subsequent process is lowered, which is undesirable. Further,
when the thickness of the electrolytic copper foil exceeds 70
.mu.m, the removal via the etching may be poor when the copper foil
is removed by the etching after the graphene is synthesized on the
electrolytic copper foil.
Further, a resistance of the copper foil after synthesis of the
graphene on the electrolytic copper foil for the graphene may be
300 .OMEGA./square or smaller. Otherwise, when the resistance of
the copper foil after synthesis of the graphene on the electrolytic
copper foil for the graphene exceeds 300 .OMEGA./square, there is a
problem that graphene is not properly synthesized on the
electrolytic copper foil.
Further, in a method for producing an electrolytic copper foil for
graphene in one embodiment of the present disclosure, plating of
the copper foil is performed in a copper electrolytic solution
under a condition that a nickel concentration in the copper
electrolytic solution is kept at 1000 ppm or lower and a chlorine
concentration in the copper electrolytic solution is kept at 1 ppm
or lower. The nickel serves as a seed when graphene grows. Nickel
is doped on the surface of the electrolytic copper foil. This helps
graphene form uniformly on the surface of the electrolytic copper
foil.
Further, in one embodiment, plating of the copper foil may be
performed in a copper electrolytic solution under a condition that
a total organic carbon (TOC) concentration in the copper
electrolytic solution is kept at 3 ppm or lower. In the present
specification, the TOC stands for Total Organic Carbon. This is the
term of the amount of carbon in the organic contents contained in
the liquid. When the TOC concentration is higher than 3 ppm, there
is a lot of impurities in the copper foil, which greatly affects
recrystallization. Thus, it is preferable that the TOC value in the
plating bath for the electrolytic copper foil has a value of 3 ppm
or smaller.
Further, when plating the copper foil, a temperature of the
electrolytic solution may be 30 to 70 degree C. and a current
density is 30 to 140 ASD. When plating the copper foil, a copper
concentration in the electrolytic solution may be 60 to 140 g/L,
and a sulfuric acid concentration in the electrolytic solution may
be 70 to 200 g/L.
The following is a detailed description of an example of the
present disclosure.
Experiment Example 1
Resistance test after graphene synthesis based on the room
temperature tensile strength of the electrolytic copper foil for
graphene according to the present disclosure, and the room
temperature tensile strength of the electrolytic copper foil after
thermal treatment thereof.
In Experiment example 1 of the present disclosure, the resistance
test after graphene synthesis based on the room temperature tensile
strength of the electrolytic copper foil for graphene according to
the present disclosure, and the room temperature tensile strength
of the electrolytic copper foil for graphene according to the
present disclosure after thermal treatment thereof was carried out
in order to measure whether the graphene synthesis is easily
performed based on the tensile strength. Table 1 below shows a
change in resistance value after the graphene synthesis based on
the thickness of the electrolytic copper foil, the TOC
concentration in the electrolytic solution, the nickel
concentration in the electrolytic solution, the tensile strength at
room temperature, and the tensile strength at room temperature
after thermal treatment.
In the present example 1 to the present example 8 in the following
table 1, the electrolytic copper foil has a tensile strength of 45
to 70 kgf/mm.sup.2 at a room temperature, and the electrolytic
copper foil after thermal treatment has a tensile strength of 20 to
35 kgf/mm.sup.2 at a room temperature. The thickness of the
electrolytic copper foil is 4 to 70 .mu.m. The plating of the
copper foil is performed in a copper electrolytic solution under a
condition that a nickel concentration in the copper electrolytic
solution is kept at 1000 ppm or lower and a chlorine concentration
in the copper electrolytic solution is kept at 1 ppm or lower. The
plating of the copper foil is performed in a copper electrolytic
solution under a condition that a total organic carbon (TOC)
concentration in the copper electrolytic solution is kept at 3 ppm
or lower. Further, in the comparative example 1 to the comparative
example 5 in the following table 1, when the room temperature
tensile strength and TOC concentration in the electrolytic solution
are outside the ranges specified in the examples of the present
disclosure. The comparative examples show measurements of the
resistance value after graphene synthesis in this context.
Referring to table 1 below, in the present example 1 of the present
disclosure, TOC concentration is 1 ppm, the tensile strength at
room temperature and the tensile strength at room temperature after
thermal treatment are 51 kgf/mm.sup.2 and 25 kgf/mm.sup.2,
respectively. In this case, the resistance value after graphene
synthesis was 180 .OMEGA./square. Further, in the case of the
present example 3 and the present example 7, TOC concentration of 1
ppm and 2 ppm, respectively. The tensile strength at room
temperature and the tensile strength at room temperature after
thermal treatment were 57 kgf/mm.sub.2 and 26 kgf/mm.sub.2,
respectively in the preset example 7. The tensile strength at room
temperature and the tensile strength at room temperature after
thermal treatment were 62 kgf/mm.sub.2 and 28 kgf/mm.sub.2,
respectively in the preset example 3. The resistance values after
the synthesis of graphene were 250 .OMEGA./square and 280
.OMEGA./square, respectively in the present example 3 and the
present example 7. It may be seen that both have a resistance value
of smaller than 300 .OMEGA./square. When the resistance value after
synthesis of graphene is smaller than 300 .OMEGA./square, this
means that graphene is easily synthesized on an electrolytic copper
foil.
On the other hand, when we refer to the comparative example 1 in
the following table 1, at TOC concentration of 100 ppm, the tensile
strength at room temperature and tensile strength at room
temperature after thermal treatment were 35 kgf/mm.sup.2 and 30
kgf/mm.sup.2, respectively. In this case, the resistance value
after the synthesis of graphene was 400 .OMEGA./square. Further, in
the case of the comparative example 5, at TOC concentration of 1000
ppm, the tensile strength at room temperature and tensile strength
at room temperature after thermal treatment were 40 kgf/mm.sup.2
and 35 kgf/mm.sup.2, respectively. In this case, graphene synthesis
was not observed.
In the case of the comparative example 1 and the comparative
example 5, the TOC concentration exceeds 3 ppm. Thereby, a lot of
impurities exist in the copper foil. This has a great effect on
recrystallization and so on such that the surface roughness of the
electrolytic copper foil is negatively affected. As a result, the
graphene synthesis is not properly performed. Referring to the
tensile strength at room temperature of electrolytic copper foil,
the tensile strength of the comparative example 1 and the
comparative example 5 is outside the tensile strength range of the
present examples. As a result, graphene synthesis is not properly
performed. Otherwise, even when the synthesis takes place, there is
a problem that graphene is not easily formed on the electrolytic
copper foil because of high resistance value.
Therefore, it may be preferable that when manufacturing the
electrolytic copper foil for graphene, the TOC concentration of
copper electrolytic solution was kept below 3 ppm, and the
electrolytic copper foil has a tensile strength of 45 to 70
kgf/mm.sup.2 at a room temperature, wherein the electrolytic copper
foil after thermal treatment has a tensile strength of 20 to 35
kgf/mm.sup.2 at a room temperature.
TABLE-US-00001 TABLE 1 Tensile strength Tensile at room strength
temperature TOC Ni at room after Resistance Thick- concen- concen-
temperature treatment after ness tration tration (kgf/ (kgf/
graphene Examples (.mu.m) (ppm) (ppm) mm.sup.2) mm.sup.2) synthesis
Present Example 1 35 1 100 51 25 180 Present Example 2 35 2 500 45
28 200 Present Example 3 4 1 450 62 28 250 Present Example 4 12 0.9
350 58 29 230 Present Example 5 18 0.8 200 55 24 200 Present
Example 6 70 3 980 47 24 150 Present Example 7 10 2 350 57 26 280
Present Example 8 10 1 450 55 26 290 Comparative 35 100 90 35 30
400 Example 1 Comparative 18 200 10 34 30 No graphene Example 2
synthesis Comparative 12 80 30 38 31 No graphene Example 3
synthesis Comparative 12 300 80 36 32 500 Example 4 Comparative 10
1000 40 40 35 No graphene Example 5 synthesis
Those of ordinary skill in the art to which the present disclosure
belongs may understand that the present disclosure may be embodied
in other specific forms without departing from the spirit or
essential characteristics thereof. It is therefore to be understood
that the above-described embodiments are illustrative in all
aspects and not restrictive.
The scope of the present disclosure is defined by the claims set
forth below rather than by the above detailed description. All
changes or modifications that come within the meaning and range of
the claims and the equivalents thereof are to be construed as being
included within the scope of the present disclosure.
* * * * *